Field of the Invention
The present invention relates to an ultrasonic transducer arrangement having a housing which is in particular in the form of a pocket, for mounting the ultrasonic transducer arrangement in a through-hole of a housing of an ultrasonic water meter. The present invention also relates to an ultrasonic water meter which uses a corresponding ultrasonic transducer arrangement.
Ultrasonic water meters in which ultrasound transducer arrangements accommodated in a separate housing are accommodated in the area of a through-hole in a housing of an ultrasonic water meter, are sufficiently well known. These devices are widely known as “bulk water meters” and have expanded nominal diameters.
Accordingly, in published, European patent application EP 2 333 495 A1 an ultrasonic water meter is disclosed, in which each ultrasonic transducer arrangement accommodated in a separate housing is placed on a through-hole which is cut into the housing of the ultrasonic water meter, and subsequently welded. Two such ultrasonic transducer arrangements are arranged so that the resulting measuring section transmits ultrasound diagonally through the through-passage channel of the ultrasonic water meter. The respective through-hole is introduced along the curved surface contour of the housing of the ultrasonic water meter using a laser. The housing of the ultrasonic transducer arrangement is open to the measuring channel of the ultrasonic water meter, so that the ultrasonic transducers are held in position in direct contact with water by the water pressure.
U.S. Pat. No. 8,438,935 B2 and published, European patent application EP 2 386 835 A1 (corresponding to U.S. patent publication No. 2011/0277558) disclose an ultrasonic flow meter, in which two ultrasonic transducer bodies are arranged opposite each other along the periphery of the housing outside the housing, in order to transmit ultrasound through a portion of the flow cross section.
U.S. Pat. No. 7,735,380 discloses a diagonal arrangement of ultrasonic transducer bodies in the outer region of the ultrasonic water meter.
This ultrasonic transducer arrangement known from international patent disclosure WO 2011/141167, corresponding to U.S. Pat. Nos. 8,904,881 and 9424,392, contains a cup-shaped housing insert through which ultrasound can be transmitted and in which a transducer body is located. The cup-shaped housing insert is inserted into a through-hole in the housing of the water meter. The transducer body in this case is positioned in the housing insert parallel to the mounting plane of the latter. The contacting of the transducer body is effected by a spring which presses against the transducer body. To fix the transducer body in the housing insert, the latter has a cap-like sealing part having an inner chamber accessible from one side for receiving the spring. The transducer body is fixed in place by mounting the lid or a circuit board positioned at the top. A corresponding ultrasonic transducer arrangement can only be used with a transducer body oriented perpendicular to the measuring channel.
Finally, published, British patent application GB 2 101 318 A discloses an ultrasonic flow meter. The transducer body in this case is positioned on the housing of the ultrasonic meter at an oblique angle to the mounting plane of the housing. To fix the transducer body to the housing wall to be radiated with ultrasound, the transducer body is encapsulated with epoxy resin. Due to pressure variations in the pipe network and temperature fluctuations in the environment, there is a risk that the transducer body becomes detached from the adjacent housing wall or that other effects occur which corrupt the measurement. Moreover, the epoxy resin causes sound to be radiated to the rear, leading to a significant loss of efficiency.